An investigation to demonstrate the effect of different sucrose concentrations on potato tissues.

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Introduction

An investigation to demonstrate the effect of different sucrose concentrations on potato tissues. OSMOSIS: Osmosis is the passage of water from a region of high water concentration through a partially permeable membrane to a region of low water concentration. My main aim is to find out if different concentrations of sucrose solutions cause the mass of a potato chip to increase or decrease. I plan to use 5 different concentrations of sucrose solutions, and for each concentration I will take 3 results. This will determine how much osmotic activity has occurred. I will then find the average weight change for each result. Finally, I will find the average weight change and the average percentage change. The Preliminary Osmosis experiment. Apparatus * Potato chips * 1 measuring cylinder * 3 test tubes * 1 test tube rack * the concentrations of sugar solutions ( 0.5M, 1.00M ) * distilled water (0.00M) * Electronic scales * 1 scalpel * 1 ceramic tile * sticky labels * paper towels * 1 ruler Method 1. I took 3 potato chips from the table, and cut them up into 3 cm lengths, using a scalpel. I had to be very careful whilst using the scalpel because it was extremely sharp. 2. Then, I placed them onto a ceramic tile to avoid any dirt reaching it. This is because dirt could hinder the progress of osmotic activity, and also the dirt could add weight, and therefore mass to the potato. 3. I then separately weighed the 3 potato chips and recorded their masses. 4. Taking a test tube rack I placed 3 test tubes in it labelling them 1, 2 and 3 using sticky labels. ...read more.

* If the sugar solution evaporates past the level of the potato, then the potato sample will have less surface area in the solution so this would make osmosis happen much slower. To stop any solution evaporating I could place a layer of cling film on top of the test tube. * I was forced to rely on imprecise tools to cut the potatoes, such as rulers, scalpels and most of all my own judgment. Some kind of machine to cut the potato chips into exact pieces would have been much more accurate. * I could also extend this experiment by repeating exactly as before. However this time I could take more results at the molarity levels eg 0.1M, 0.2M, 0.3M, 0.4M, 0.5M, 0.6M, 0.7M, 0.8M, 0.9M, and 1.00M. These solutions would produce more accurate results. To extend the investigation I could use concentration s like 0.05M instead of 0.1M. This would increase the accuracy of the entire experiment including my graph. * Another way to extend the investigation could be using different plant tissues. For example a carrot tissue or an apple tissue, or, I could keep my potato investigation and compare it to a carrot or an apple. I could then decipher which tissue is most liable for osmosis to occur. * Also, to extend the investigation I could vary the temperature and then put the potatoes in say 10 ?C, 20 ?C, and 30 ?C water baths. The same investigation rules, like the variables and the time allocated for osmosis to take place, 24 hours, still apply. But overall, given the apparatus that we got to carry out the test, I think this experiment turned out to be very successful, and I'm very pleased with my results because they backed up my predictions. Mohammed Rattansey LVE 1 ...read more.

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